Other than its farcical beta staus (over four years and counting) Gmail is really rather good... and it's just gotten even better.
Showing it can compete with desktop clients like Microsoft Outlook and Thunderbird on their own turf, Gmail now has a highly welcome offline mode. By using the potentially game changing Google Gears - which has already been integrated into Google Documents and Chrome - it means Gmail users can open their accounts in their browser, search email and even compose replies offline. All performed actions are then synchronised with Gmail the moment the computer goes online.
In essence Google has seamlessly made Gmail both an online web service and an offline desktop email client at a single stroke. In fact, the new functionality even comes into effect when you're using a slow or unreliable Internet connection with 'flaky connection mode'. With this Gmail will use local cache as if you were disconnected, but still synchronizes your mail with the server in the background as and when the connection is available. Clever stuff.
To get Gmail offline feature you simply need to enable Google Labs, then go to settings, select 'Enable' next to 'Offline Gmail' and save the changes. As ever Google is rolling out the feature incrementally (US and UK users are prioritised), so the option may not be there immediately - but patience young grasshoppers.
Rivals feel free to start shaking any time...